7th November 2020 at 11:09am
| purpose | filter the input by fundamental category |
|---|---|
| input | a selection of titles |
| parameter | C=a category |
| output | those input tiddlers that belong to category C |
! output | those input tiddlers that do not belong to category C |
Learn more about how to use Filters
The parameter C is one of the following fundamental categories:
| Category | Matches any tiddler title that... |
|---|---|
current | is the current tiddler |
image | has an image ContentType |
binary | has a binary ContentType |
missing | does not exist (other than possibly as a shadow tiddler), regardless of whether there are any links to it |
orphan | has no hard links to it |
shadow | is a shadow tiddler, regardless of whether it has been overridden with a non-shadow tiddler |
system | is a system tiddler, i.e. its title starts with $:/ |
tag | is in use as a tag |
tiddler | exists as a non-shadow tiddler |
variable | Introduced in v5.1.20 exists as a variable (whether or not that variable has a non-blank value) |
blank | Introduced in v5.1.20 is blank (i.e. is a zero length string) |
draft | Introduced in v5.1.23 is a draft of another tiddler. Synonym for [has[draft.of]] |
If C is anything else an error message is returned. Introduced in v5.1.14 if C is blank, the output is passed through unchanged (in earlier versions an error message was returned).
!is[tiddler] is a synonym for is[missing], and vice versa.
When is[missing] is the first operator in a run, its output is always empty. And when is[shadow] comes first, it outputs only those shadow tiddlers that have been overridden. This is because the initial input to a run contains only non-shadow tiddlers.
The all operator is similar to is, but its scope is the whole wiki.